Miami - Top-ranked Dustin Johnson and five-time major champion Phil Mickelson advanced to the World Golf Championships Match-Play Championship quarter-finals with impressive triumphs on Saturday.
Reigning US Open champion Johnson defeated fellow American Zach Johnson 5 and 4 while Mickelson downed Australia's Marc Leishman 4 and 3.
Johnson, who has led after all 60 holes he has played this week, won three of the last four holes on the front nine and closed out the match with back-to-back birdies.
"I guess I'm putting a lot of pressure on them," Johnson said. "I'm just playing pretty solid golf, not making any mistakes; made a lot of birdies; hit a lot of fairways; a lot of good shots into the greens. I just need to keep it in the fairways, keep hitting good shots."
Mickelson birdied three of the last four holes on the front nine to seize command at 4 up and remained unbeaten this week, but the 46-year-old left-hander has yet to play the final three holes.
"I'm certainly a little bit worried because I know there's going to be a key match that's going to go down to the last few holes and I'm not as comfortable on those holes as I'd like to be," Mickelson said. "But I love the fact that I'm able to be rested and ready to play because I think it's helping me get off to a good start."
In Saturday afternoon quarter-finals, Johnson faces the only other top-eight seed in the quarter-finals, Swedish eighth seed Alex Noren, who defeated American Brooks Koepka 3 and 1.
Mickelson will play Bill Haas, who eliminated US compatriot Kevin Na 1 up.
Danish longshot Soren Kjeldsen also made it into the last eight.
Kjeldsen, seeded 62nd in the original field of 64, shocked Rory McIlroy in his group stage opener on the way to the knockout rounds at Austin (Texas) Country Club and continued his hot hand on Saturday by ousting American William McGirt 5 and 4.
He next faces Spaniard Jon Rahm, who eliminated American Charles Howell 6 and 4. At 22, Rahm could become the youngest winner of any WGC title.
"This morning was definitely the best I played as a whole," Rahm said. "The first few days I hit the driver really well the whole round and that's probably why I won. Today started a little shaky. I got birdies out of bad drives. The difference today is that I was making the putts."
The other quarter-final pits England's Ross Fisher against Japan's Hideto Tanihara. Fisher advanced by downing two-time Masters champion Bubba Watson 4 and 3 while Tanihara defeated England's previously unbeaten Paul Casey 2 and 1.
Fisher finished off Watson by holing out from a greenside bunker at 15.
Tanihara, in his first match-play start, stayed unbeaten by making a birdie to win the 16th and then putting his tee shot at the par-3 17th four feet from the cup, setting up the winning birdie putt after Casey failed to convert from 12 feet.